1. Field of the Invention
The present disclosure relates to a strip used for analyzing sample and a cartridge for the same.
2. Description of the Related Art
Diagnostic methods and devices for qualitative or quantitative measurement of a finite amount of materials in biological samples such as blood or urine have been developed for the last 30 years. Since an introduction of radioimmunoassay (RIA) using radioisotopes in the 1950s, other assays such as enzyme-linked immunosorbent assays (ELISA) were also developed in the 1970s and 1980s.
For the analysis of proteins, immunological methods based on an antigen-antibody reaction such as ELISA and immunochromatography have been widely used. However, it requires a considerable amount of time to prepare samples and to analyze them.
For the analysis of nucleic acids, it is important to detect the presence of a particular DNA or RNA sequence of interest in the sample. Examples of such methods include the Southern or Northern blot analyses using a probe amplified by a polymerase chain reaction. However, it requires a considerable amount of time to analyze in addition to problems such as repeated experiments are required to find an optimal condition for accurate and reproducible results. Furthermore, the results are subject to external conditions such as time, temperature, composition of nucleic acid sequence employed for the hybridization, which requires the involvement of well-trained experts for the analysis.
Particularly, in the case where accurate detection results are imperative for a reliable diagnosis, there is a need to develop methods, which can produce accurate, reliable and reproducible results with high sensitivity and specificity in a relatively short period of time. For example, the diagnosis cervical cancer, which relies on the nucleic acid detection, is on the rise. There are needs to develop detection system, which is able to provide a more sensitive and reliable results in a rapid and convenient manner to replace the conventional system.
One of the recently developed methods to detect nucleic acids or proteins in a sample is a lateral flow assay based on chromatography. The lateral flow assay is widely used in a variety of fields such as pregnancy test and cancer diagnosis to detect proteins, nucleic acids or microorganisms.
Korean Patent No. 1115014 relates to a chromatography system to detect nucleic acids and discloses a strip comprising a solid support, a chromatographic medium, a sample pad and an absorption pad. When an aliquot of sample is loaded to the sample pad, the sample moves through the chromatographic medium to the absorption pad by capillary action during which a component of interest in the sample binds to capturing nucleic acids immobilized on the medium. In such a conventional strip, exact amount of samples are loaded directly onto a sample pad to obtain a reproducible result. Thus samples to be loaded need to be measured as accurately as one microliter unit, which leads to the inconveniences to the user and is the cause for error in the detection results. Further changes in the amount of sample to be loaded should be accompanied by corresponding changes in the structures of the strips and cartridges therefor.